Muscle stimulator



July' 7,v 1970 E. CORTINA MUSCLE STIMULATOR Filed April 17, 1967 2 Sheets-Sheet 1 vkw @iwi mw ...QE o 8.0.2.. c mkw Qd S l-) 25. )EE I` 25.-- ll-- 'INVENTUR ELOY CORTINA BYW AGENT July 7, 1970 E. CORTINA MUSCLE STIMULATOR 2 Sheets-Sheet 2 Filed April 17, 1967 KNVENTOR. ELOY @ORTINA AGENT United States Patent O 3,518,996 MUSCLE STIMULATOR i Eloy Cortina, 1655 10th St., Santa Monica, Calif. 90404 Filed Apr. 17, 1967, Ser. No. 631,207 Int. Cl. A6111 1/36 U.S. Cl. 12S- 422 2 Claims ABSTRACT F THE DISCLOSURE A muscle stimulator is described wherein a generator of a train of relatively low frequency, generally spiked pulses of short duration compared with the interval between pulses is provided. The pulse train is operated continuously, or selectively, under the control of a multivibrator for predetermined on and off periods. The stimulator has a plurality of outputs each with an individual output control. It employes all transistors in its active circuits and may be operated from battery power sources or from the A-C power lines.

BACKGROUND OF THE INVENTION This invention relates to electro-medical apparatus generally, and more particularly to an electric oscillation generator of novel design for use as a stimulator of muscle activity.

It is well known that by an electric stimulation of nerves, muscles can be excited to contract in a manner very like the voluntary contraction of muscle an individual experiences during various physical exertions and activities in a persons normal waking day.

Some muscles are not usually exercised, especially by persons whose general activity is sedentary in nature and who thereby develop flabby muscle tissue. Frequently this abby tissue gives the person an appearance of being fat when in fact it is only a condition requiring the toning up of the sagging or fiabby muscle tissue to regain a more pleasing appearance.

The above mentioned electrical stimulation of muscles through excitation of the nerves which control them can be accomplished by the application of stimulating pulses of electric character through a persons body exterior.

The excitation of nerves is an all or none action, That is, the nerve is either excited or not, depending upon the intensity of the stimulus applied to it. Once excited, no further increase in the intensity of the stimulus will produce further transmission of the impulse leading to the nerve-directed activity. The muscle, for example, which is responsive to the nerve stimulated by the stimulus impulse, once reacting, remains in the reactive condition until the stimulus is removed.

To those familiar with electronic apparatus, this nervemuscle stimulus behavior may be appreciated as resembling the behavior of a conductive electronic device normally biased for non-conduction, which, when the bias is overcome by an appropriate signal applied thereto, is fully activated to become conductive, and no further increase in the bias overcoming signal will increase the conduction. The device then remains conductive until the stimulating signal is removed, at which time the device returns to its non-conductive condition.

These nerve-muscle bias-overcoming signals, as has been pointed out above, may be applied to appropriate areas of the body exterior in the form of electrical impulses either applied for an extended period to produce a sort of massaging effect, or they may be applied over relatively short alternate periods of application and removal of the electric impulsive stimulating signal to produce repeated contraction and relaxation of the muscles being stimulated, generating thereby an involuntary form 3,518,996 Patented July 7 1970 ice SUMMARY OF THE INVENTION This invention contemplates a novel electrical impulse generating system and means for applying the impulses so generated to the appropriate areas of a persons body by which the above described massaging and exercising effects upon the muscles maybe selectively achieved, as desired. The impulses generated by the new system are uniform, relatively narrow spiked pulses, or alternatively, may be rectangular pulses of short duration separated by intervals of somewhat longer duration. These pulses are hereinafter described as the higher frequency pulses. Additionally in the new system, longer duration pulses are produced to be used as interruption pulses of relatively low frequency to `be applied to the narrow spiked pulse generator for on-off operation thereof.

In the electrical impulse generator according to the invention, a novel oscillator for producing the spiked narrow or rectangular pulses and a power amplifier have been devised utilizing semi-conductor devices. The resulting pulses are applied to a plurality of separate outputs, each of which may be individually adjusted as to output level. To each of the respective outputs electrodes may be attached. These electrodes are adapted for positioning on the body exterior on the areas where the muscles it is desired to stimulate will respond.

The impulse generator includes also a semi-conductor very-low frequency switching signal generator which may be selectively applied to the oscillator so as to turn it on and off for appropriate periods. Means may be provided to adjust the periodicity rate of the switching signal generator so as to produce uniform on and off periods for the oscillator, or the olf periods may be made longer than the on periods at will, or vice-versa.

The above described objects of the invention and others will be more clearly understood from the specification which follows, taken together with the drawings and the appended claims.

It should be clearly understood that the embodiments shown and described are representative of the novel concepts of the invention and should not be construed as limiting the invention thereto since those skilled in the arts appertaining to the invention will 'be able to device other embodiments in the light of the teachings herein within the ambit of the claims.

DESCRIPTION OF THE INVENTION FIG. 1 is a schematic circuit diagram of a muscle stimulator according to this invention;

FIG. 2 is a diagram of a typical waveform train such as may be produced by the circuit of FIG. 1 during continuous operation thereof;

FIG. 3 is a schematic circuit diagram of an alternative adjustable high-frequency pulse generator which may be used as part of the circuit arrangement shown in FIG. 1;

FIG. 4 (A through F) illustrate waveforms to be observed at various points in the circuit shown in FIG. 1;

FIG. 5 is a perspective view of a muscle stimulator instrument according to the invention showing its installation in a carrying case also designed to accommodate the accessory electrode pads which are also illustrated;

FIG. 6 is a plan view of one of the electrode pads shown in FIG. 5; and

FIG. 7 is a cross-section through 77 of FIG. 6.

In FIG. 1 a schematic circuit diagram of the muscle stimulator is shown. The stimulator circuit can be seen to include an oscillator 10, an amplifier 11, a switching circuit 12, and a power supply 13.

The oscillator 10 utilizes a unijunction transistor 20 which has first base terminal 21, a second base terminal 22 and an emitter 23. A first base load resistor 24 is connected between first base terminal 21 and a positive potential line 30. A second base load resistor 2S is connected'between second base terminal 22 and a negative potential line 31. A series resistance combination 28, 26 is connected between an armature terminal 41 of a single pole `double throw switch 40 and emitter terminal 23. A capacitor 27 is connected between the junction 29 of resistors 26, 28 and negative line 31.

Switch 40 has a terminal 42 and a terminal 43. Terminal 43 is connected to positive potential line 3i) so that when the arm 44 of switch 40 is connected to terminal 43 identified with M, unijunction transistor 20 operates as a continuous oscillator generating a saw-tooth wave. The frequency of oscillation is a function of the values of capacitance of capacitor 27 and resistance of resistor 28. The resistance of resistor 28 may be made variable as indicated by dashed line 28a in order to provide setting of the frequency of oscillator as desired. Resistor 26 functions as a current limiting resistance in the emitter 23 circuit. When arm 44 is connected to terminal 42 identified with T, the oscillation of unijunction transistor oscillator 10 is interrupted so as to be operative only when transistor 50 is conductive as hereinafter described.

Amplifier 11 includes a transistor 60 shown here as an NPN device, but which may as well be a PNP device as would be obvious to those skilled in this art. If a PNP device is used, connections of the transistor will have different polarities. The collector 61 of transistor 60 (NPN) is connected through the primary 62 of an output transformer 63 to a positive potential line 32 at a different potential than that at line 30. Transformer 63 has four identical independent secondary windings 64, a, b, c, d, across each of which is connected respective potentiometers 65, a, b, c, d. From respective variable arms 66, a, b, c, d of potentiometers 65a-d output jacks 67, a, b, c, d are connected. Each respective jack 67a-d has a respective return connection to one end 68, a, b, c, d, of potentiometers 65a-d. It is to be noted that as a result of the individual character of the windings 64a-d each of the output terminals 67a-d will provide independent and separately usable signals as hereinafter delineated.

The base 69 of transistor 60 is directly coupled to second base 22 of unijunction transistor device 20.

The emitter 70 of transistor 60 is connected to negative potential line 31.

The operation of transistor amplifier 60 is essentially conventional with the exception of the direct coupling of base 69 to second base 22 of unijunction transistor 20. The signals appearing on second base load resistor 25 drive amplifier 60; the amplified output appearing across primary winding 62 of transformer 63. Diode 71 is connected across primary 62 to suppress inverse polarity pulses so that only unipolar pulses are present in primary 62 to generate in each of secondaries 64a-d the pulse waveform shown in FIG. 2.

In .the dashed block 12, PNP transistors 51, 50 are shown connected in a conventional multivibrator configuration. Capacitors 52, 53 and resistors 56, 57 are the frequency determining elements of the multivibrator operation, resistors 54, 55 are collector load resistors. The frequency determining elements 52, 53, 56, 57 can be made adjustable so as to provide adjustment of the operating frequency of multivibrator 12.

In normal use oscillator 10 operates at frequencies in the range of 20 through 100 pulses per second. Multivibrator 12 is normally used at much lower rates from about lO'per minute to about 30 per minute. It is to be understood that these pulse rates are the rates at which the oscillator 10 can be turned on and off when arm 44 of switch 40 is connected to terminal 42. It is to be noted that terminal 42 is connected with the collector of transistor 50. Thus when transistor 50 is conductive during the multivibrator operation oscillator 10 is on. When multivibrator transistor 50 is not conductive then oscillator 10 is olf. This is because during the conductive condition of transistor 50 the emitter 23 of unijunction transistor 20 is returned through transistor 50 to the positive potential line 30 and the oscillator circuit is thereby completed.

The operation of multivibrator transistors 50, 51 can be adjusted by the appropriate values of resistors 56, 57 and capacitors 52, 53 so that either the on periods of oscillator 10 are longer than the off periods, or the reverse condition may be effected in which the off periods are longer than the on periods, or the periods of on-ofic operation may be made uniform as desired for particular medical requirements.

The system hereinabove described may be powered either from the A-C power lines through a rectifier circuit, or batteries may be used. The on-off operation of the power supply 13 is normally under the control of a timer which is set for a predetermined treatment interval.

A novel switching arrangement has been incorporated in this instrument so that the user may at will employ the self-containing battery 81 or the power line 83 and in either case have the advantage of the same timer switch 80. This is accomplished through the kuse of a double pole double throw switch l82.

Switch 82 includes switch arms 87 and 90 which are manually operable to Contact either terminals 86 and 89 or terminals 88 and 91. In the first instance power line wire 85 and primary return wire 92 from power transformer 97 are connected through arms 87 and 90 and terminal contacts 86 and 89 to timer 80. Timer switch 80 is a typical mechanical clock driven switch of conventional design similar to those well-known to the photographic industry for operating exposure lamps for predetermined intervals and in household equipment for cooking timing functions.

Power line wire 83 is connected through a fuse 94 to the other side 93 of the primary of power transformer 97.

So long as timer switch 80 is closed by its clock mechanism when switch 82 is in the power line position A-C power from the line is applied to transformer 97 and induced in the secondary thereof to be rectified by full wave semiconductor rectifiers 98 and 99. A D-C potential is thus developed on line 32. When the timer switch is open power is removed.

Resistor 101 connected between lines 30 and 32 and capacitors and 102 provide filtering and voltage dropping action so that the D-C voltage on line 32 is higher than that on line 30.

When the arms 87-89 of switch 82 are in contact with terminals 488 and 91 thereof timer switch 80 is connected between line 96 and the positive terminal of battery 81 to apply the positive potential through switch 80 to line 32. The negative terminal of battery 81 is permanently connected to negative line 31 which is common to both A-C rectified and battery D-C power supplies.

Because of the polarization of rectifiers 98 and 99, there will be no efiect upon the battery 80 or transformer 97 in the configuration used; they are non-conductive for the polarity of battery 81 with respect to lines 96 and 31 and diodes 98 and 99.

In the waveform diagrams of FIGS. 4A through 4F, the letter designations A through F correspond to the letter designations A through F appearing at various points in the circuit diagram of FIG. 1.

For example, the rectangular waveform shown in FIG. 4A is to be observed at A the collector of transistor S1, while the waveform of FIG. 4B is to be observed at the collector B of transistor 50. The saw-toothed waveform shown at 4C may be observed at C in FIG. lv across capacitor 27. The spiked waveform shown in FIG. 4D is observed at E on the collector 61 of transistor 60 and across the primary 62 of transformer 63.

The output waveform shown at 4F appears at each of the output jacks 67a--67d as indicated by F.

When switch arm 41 of switch 40 is connected to terminal 43 a Continuous train of pulses as shown at 4F appears across each of controls 65a-d and each of respective secondary winding between 46fm-d and 68a-d,

.and at output jacks 67a-d (points F).

When switch arm 41 is connected to terminal 42 as lshown in FIG. 1 a train of pulses such as shown in FIG. 4F occurs continuing only for the period of the :pulse shown in FIG. 4B, a period of .75 second. If the values of resistors '56,57 and/or capacitors 52, 53 are changed, the'fperiod of the pulse of FIG. 4B may be shortened orlengthened, giving a longer or shorter train of pulses as 4F.

Ordinarily, for general public .use of the muscle stimulator, a lixed` ypulse duration for pulses shown at 4F and at l4B is employed in instruments made available to the gen- `FIG. 3 variable resistor 110 provides for duty cycle vvariationsorselection and variable resistor 130 can be adjusted to provide for different pulse repetition rates yas'desired for the pulses shown at 4D, E and F.

. `InFIG. 5 `there is shown a representative encasement `.for a muscle vstimulator according to this invention. The

encasement includes a relatively deep case 150 to receive the electronic equipment and store the accessories of `the invention device, and cover 151 attached removably by hinges 15.4. Trunk type clasp 152, 153 interfit to hold cover 151 on case 150 when the case is closed. Compartments 15S-158 are provided to receive electrode pads 159-162 for storage thereof. The pads shown at 159, 160 are folded as they are stored in compartments such as 155-158. The pad 161 is face down, and pad 1l62 is face up. On the backs of the pads 159, 160, 161 loops are provided so that the electrode pads may be assembled on body or limb encircling belts (not shown) sueh as are well known in the surgical and therapeutic arts. Such belts may be stored in compartment 164.

A different form of electrode structure is shown in FIG. 5 at 167. This is `known as a facial electrode and its two terminal sponge pads 168, 169 are positioned so as to stimulate and exercise facial muscles when applied to a patients face. The sponge pads 168 and 169 may be moistened with conductive jellies or fluids. It is said that this tones the facial muscles which vfor storage of electric power cord 84, 85 and covered `compartment 166 for storage of the battery 81 (FIG. 1). ,Qn the instrument panel 173 are identified the controls, jacks, and switches forming the control devices identi- ,tied in the circuit of FIG. 1. These control devices and .jacks bear the same reference characters in FIG. 5 as "those in FIG. 1 and correspond accordingly.

' In FIGS. 6 andv 7 are shown respectively a face plan 4view and cross-section (7 7) through a typical body land limb musculature electrode pad as such as shown in FIG. 5 at 159-162. The unit 162 is selected for the ensuing description:

The electrode pad 162 comprises a pair of electrode elements 180, 181 forming an overlapping double oval enclosure 174 in which are inserted pairs of conductive rubber pads 175 each backed by a metal contact plate 179 (see cross-section diagram, FIG. 7). The conductors of electric connection leads 176 are soldered to the metal contact plates 179 and terminate in a plug 178 which may be inserted into any one of the jacks 67a-d. Leads 176 are covered with insulation.

In use the muscle stimulator is operated by inserting the plugs 178 of pads 159-1162 or similar pads into selected jacks 67ad in panel 173. lf the unit is operated on A-C power lines the cord 84-85 is plugged into the A-C outlet and switch 82 positioned for A-C operation. If the internal battery 81 is used switch 82 is positioned for battery operation. The equipment is rendered operative in either battery or A-C operation by rotating time switch to its desired time of operation. The operation will continue for this selected time interval. The amplitude of output pulses applied via electrodes 159- 162 is adjusted by controls 65, 66a-d. The continuous (massage) operation of the pulse output or interrupted output (tone) operation is selected by the appropriate positioning of switch 40.

There has been described hereinabove a signal generator for muscle stimulation comprising in combination a unijunction transistor oscillator 10, a power amplifier 11 with multiple outlets, a multivibrator switching pulse generator 12 switching means for selectively operating the oscillator in a continuous or an interrupted mode, and a power supply 13 selecitvely operable from either a battery or an A-C power line rectifier source under the switching control of a clock operated timer for predetermined intervals.

What is claimed as new is:

1. In a muscle stimulator a unijunction transistor having a pair of bases and an emitter, one of said bases having an output load resistor connected thereto, said emitter having a frequency determining network connected thereto;

a source of potential having respective negative and positive potential lines, the negative potential line being connected to said output load resistor, and the positive potential line being connected to the other of said bases as a circuit return;

an amplifier circuit connected to said load resistor and having an output transformer in the output of said amplifier with a plurality of outputs;

an astable transistor multivibrator; and

a circuit selection switch connected between said multivibrator, said frequency determining network and said positive potential line so that in one position of said switch said emitter and the frequency determining network can be connected to said multivibrator to the turned on and off at frequency of said multivibrator frequency so that said unijunction transistor will oscillate intermittently at a frequency determined by said frequency determining network, an in another position of said switch, said frequency determining network is connected to said positive potential line so that the unijunction transistor will oscillate continuously at said frequency of said frequency determining network,

said respective continuous or intermittent oscillations being produced in said plurality of outputs of said output transformer.

2. A muscle stimulator comprising an oscillator operable at one oscillation frequency a single pole double throw switch;`

an amplifier connected to said oscillator;

an output transformer connected to said amplifier;

a multivibrator for generating pulses at a lower frequency than said one frequency:

at least one electrode pad;

a power supply means connected to an A-C supply source;

a battery power source; and

a mechanically settable timing switch means connected between said power supply means, and said battery and said oscillator, multivibrator, and ampliiier, so as to selectively apply said power supply means or said battery to said oscillator multivibrator and said amplier for a selected time interval set on said timing switch, so as to operate said stimulator for said selected interval.

and Isaid single-pole double throw switch including an arm an first and second poles, said arm being connected to said oscillator and said respective poles being connected to said multivibrator and to said power supply means respectively so that said oscillator can `be maintained selectively in a continuously operating condition or in an interrupted oscillating condition at the frequency of said pulses, and said transformer being connected to said at least one of said electrode pads for applying said selected continuous or interrupted oscillations to muscles of the body 8 when said pad -is positioned on said muscles to stimulate the contraction and relaxation of said muscles during said interrupted operation and massaging operation during said continuous operation of said oscillations. f l.

References Cited UNITED STATESPATENTS 'f 2,838,672 6/1958 Paust v'128;422 3,025,858 3/1962 Browner 128 42,2 3,108,597 10/1963 Mosseta1. 128422 3,279,468 10/1966 Levine 128 v-f11o FOREIGN PATE'S" i y 826,766 1/1960 Great Britain.v

WILLIAM E. KAMM, Primary Examiner 

